Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Release of Endogenous and Accumulated Exogenous Amino Acids from Slices of Normal and Climbing Fibre-Deprived Rat Cerebellar Slices (1983)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 41 (1983), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: Efflux of various amino acids from slices of rat cerebellar hemispheres was determined under resting or depolarizing conditions. It was increased under high K+(50 mM) as compared to low K+ (5 mM) conditions by 1258 pmol/mg protein for aspartate, 478 for γ-aminobutyric acid (GABA), 44,693 for glutamate, and 615 for glycine. These were significantly higher than the corresponding values obtained under low-Ca2+ (0.1 mM), high-Mg2+ (12 mM) conditions, whereas for 11 other amino acids the K+-induced efflux was similar under normal and low-Ca2+ concentrations. The K+-induced efflux of exogenously accumulated l-[3H]aspartate, d-[3H]aspartate, and l-[3H]glutamate was higher by factors of 2, 5.8, and 6.3, respectively, under normal Ca2+ conditions, as compared with low-Ca2+, high-Mg2+ conditions. After climbing fibre degeneration induced by destruction of the inferior olive with 3-acetylpyridine, release of endogenous aspartate and exogenous l-[3H]glutamate and d-[3H]aspartate was significantly reduced, by 26%, 38%, and 27%, respectively. These results support the hypothesis that climbing fibres may use aspartate or a related compound as a neurotransmitter. In rat cerebellar tissue, l-[3H]glutamate and l-[3H]aspartate differ in several aspects: (1) l-[3H]glutamate uptake was 4 times higher than that of l-[3H]aspartate; (2) fractional rate constant of K+-evoked release of l-[3H]aspartate was 7%× 2.5 min−1. and of l-[3H]glutamate 36%× 2.5 min−1; and (3) specific activity of l-[3H]glutamate in the eluate collected during K+ stimulation was 3.5 times the value in the tissue, whereas for l-[3H]aspartate, specific activities in the eluate and tissue were similar.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1983.tb00871.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Excitatory Amino Acid Pathway from the Hippocampus to the Prefrontal Cortex. Contribution of AMPA Receptors in Hippocampo-prefrontal Cortex Transmission (1992)
    Oxford, UK : Blackwell Publishing Ltd
    European journal of neuroscience 4 (1992), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Previous experiments in the rat have demonstrated that field CA1 and the subiculum project to the prefrontal cortex and that this direct unilateral pathway is excitatory. In the present study, anatomical and electrophysiological approaches were used to determine the transmitter mediating the excitatory responses in prefrontal cortex neurons to low-frequency stimulation of the hippocampus. The method of selective retrograde d-[3H]aspartate labelling was used to identify putative glutamatergic and/or aspartatergic hippocampal afferent fibres to the prefrontal cortex. Unilateral microinjection of d-[3H]aspartate into the prelimbic area of the prefrontal cortex resulted in the retrograde labelling of a fraction of hippocampal neurons. Some labelled cell bodies were distributed in field CA1 and the subiculum but larger numbers of neurons were detected in the ventral and intermediary subiculum. In a second series of experiments, the excitatory transmission from the hippocampus to the prefrontal cortex was pharmacologically analysed to provide further evidence for the involvement of glutamate and/or aspartate in the pathway. All prefrontal cortex neurons responding to the stimulation of the hippocampus were activated by selective agonists of the glutamate receptor subtypes α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) and N-methyl-d-aspartate (NMDA), and these effects were selectively antagonized by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and 2-amino-5-phosphonopentanoic acid (APV) respectively. Most of the excitatory responses of prefrontal cortex neurons to single and paired-pulse stimulation of the hippocampus were antagonized by CNQX. APV only affected the excitatory response in a few cells. These results suggest that the hippocampal input to the prefrontal cortex utilizes glutamate and/or aspartate as a transmitter. Even though prefrontal cortex neurons responding to the stimulation of the hippocampus appear to have both AMPA and NMDA receptors, low-frequency stimulation of the hippocampo-prefrontal cortex pathway activates cortical neurons mostly through AMPA receptors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1460-9568.1992.tb00154.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    REGENERATION OF SEROTONIN NEURONS IN THE RAT BRAIN AFTER 5,6-DIHYDROXYTRYPTAMINE-INDUCED AXOTOMY (1978)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 305 (1978), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1978.tb31534.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Serotoninergic synapses on ependymal and hypendymal cells of the rat subcommissural organ (1979)
    Springer
    Journal of neurocytology 8 (1979), S. 445-467 
    Details
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The nervous input to the subcommissural organ (SCO) of the rat has been investigated with Falck—Hillarp fluorescence histochemistry and electron microscopical techniques. Previous fluorescence histochemical observations of a dense plexus of serotoninergic nerve fibres in relation to the basal SCO were confirmed. Electron microscopically, unmyelinated fine varicose axons ranging in size from 0.1–0.6 μm were observed to penetrate into the SCO hypendyma. Boutons and presynaptic varicosities filled with a diversity of round and elongated clear vesicles, and occasional large dense cored vesicles establish asymmetric (Gray's type I) synaptic contacts with the basal processes and somata of the SCO ependymal and hypendymal cells. A typical varicosity in synaptic contact with an SCO cell contains a population of approximately 85% clear, elongated vesicles 45 × 60 nm in diameter, 15% clear, round vesicles 50 nm in diameter, and 1–2% large dense cored vesicles with a vesicle diameter of about 85 nm and a dense core diameter of 50–55 nm. The mean length of the postsynaptic membrane specialization was found to be 0.5 μm. Experiments with specific neurotoxic drugs revealed that the nerve terminals in synaptic contact with the SCO cells are identical to the fibres of the serotoninergic plexus identified fluorescence histochemically. Thus, an intraventricular injection of either 5,6-dihydroxytryptamine or 5,7-dihydroxytryptamine induced typical degenerative changes in most of the boutons in synaptic contact with the SCO cells, and also a disappearance of the yellow fluorescent nerve plexus. It is concluded that the SCO of the rat receives a dense plexus of serotonin-containing nerve fibres which form typical synaptic contacts with the specialized ependymal cells of the SCO and that these fibres may constitute the only direct nervous input to the organ. The degeneration of the serotoninergic synapses elicited a long-lasting, pronounced increase in the secretory activity of the SCO. Despite long survival times after the treatment with neurotoxic drugs, we found no evidence of regenerative restitution of the serotoninergic innervation nor normalization of the secretory activity of the SCO. The observed inverse relationship between secretory activity and serotoninergic innervation is in line with previous observations which indicate that the 5-hydroxytryptamine input to the SCO ependymal and hypendymal cells exerts a powerful inhibition on their protein synthetic machinery.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01214802
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Innervation and reinnervation of rat inferior olive by neurons containing serotonin and substance P: An immunohistochemical study after 5,6-dihydroxytryptamine lesioning (1987)
    Springer
    Journal of neurocytology 16 (1987), S. 155-167 
    Details
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Serotonin (5-HT) and substance P (SP) immunoreactive axon terminals were visualized in the inferior olivary complex (IOC) of adult rats, 1 to 2 weeks or 6 to 12 months after cerebro-ventricular injection of 5,6-dihydroxytryptamine (5,6-DHT). In normal or saline-injected controls of the same age, there was some overlap between the respective distributions of 5-HT- and SP-immunostained axonal varicosities among the various subdivisions of IOC. At short time intervals after the 5-HT axotomy, almost as many degenerating axonal profiles showed immunoreactivity to SP as to 5-HT throughout the IOC, suggesting the coexistence of both transmitters within the same fibres. A few areas continued to exhibit characteristic patches of ‘normal-looking’ SP immunoreactivity, consistent with a distinct innervation by SP fibres without coexistent 5-HT. At prolonged survival times after 5,6-DHT treatment, there was a massive increase in the number — and striking similarity in the distribution — of IOC axonal varicosities immunostained for SP as well as for 5-HT. This neo-innervation involved certain subdivisions of the IOC normally receiving fibres of either type (e.g. dorsal accessory olive), but also others normally poor in 5-HT and/or SP (e.g. medial accessory olive). It remains to be determined if this abundance of 5-HT-SP terminals in the ‘hyperinnervated’ IOC reflected a particular capacity to express both transmitters in regenerating 5-HT neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01795300
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Serotoninergic axon terminals in the rat dorsal accessory olive: Normal ultrastructure and light microscopic demonstration of regeneration after 5,6-dihydroxytryptamine lesioning (1981)
    Springer
    Journal of neurocytology 10 (1981), S. 1009-1027 
    Details
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The serotoninergic innervation of the lateral portion of the dorsal accessory nucleus of inferior olive (DAO) was studied using high resolution radioautography after intraventricular or intracisternal administration of tritiated serotonin ([3H]5-HT). In normal adult rats, the axonal varicosities labelled with [3H]5-HT were of round-elongate shape and averaged 0.6–1.0μm in diameter. They contained microcanaliculi (15–25 nm in diameter), tubular-vesicular elements (25–40 nm) and large granular vesicules (80 nm), as well as mitochondria and smooth endoplasmic reticulum. Among 750 thin-sectional profiles of labelled varicosities, only 5% showed a differentiated area of membrane specialization which suggests that not more than one out of 7–8 varicosities was engaged in a synaptic junction. This serotoninergic innervation was therefore categorized as non-junctional. There were nevertheless certain structural features suggestive of polarity even in the ‘non-synaptic’ serotoninergic varicosities of the lateral DAO: many labelled profiles exhibited aggregation of their microcanalicular and tubular-vesicular organelles against a part of their membrane apposed to a dendritic process, while the remainder of their periphery was usually surrounded by glia. These observations reinforced the supposition that non-junctional as well as junctional serotoninergic varicosities might release transmitter. Counts in light microscope radioautographs indicated that the lateral DAO of normal rat receives about 4.5 million serotoninergic varicosities per mm3. Denervation by intraventricular 5,6-dihydroxytryptamine (5,6-DHT) was severe, leaving only 0.45 million per mm3 after five days. It was followed by rapid regrowth, however, since an approximately normal number of serotoninergic varicosities was again measurable two months after 5,6-DHT. The growth process continued further, and six months after 5,6-DHT, the lateral DAO exhibited a ‘hyperinnervation’ of 12.6 million varicosities per mm3. This re-establishment of a serotoninergic innervation was in line with our hypothesis concerning the factors influencing the course of neuroplasticity. According to this hypothesis, innervations of the non-junctional variety may regenerate after neurotoxic lesioning, whereas those making numerous synaptic connections are replaced by local sprouting of intact afferents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01258527
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Neurotoxic destruction of the serotoninergic innervation of the rat subcommissural organ is followed by reinnervation through collateral sprouting of non-monoaminergic neurons (1979)
    Springer
    Journal of neurocytology 8 (1979), S. 469-480 
    Details
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Specific neurotoxic destraction of the serotoninergic innervation of the subcommissural organ of the rat is followed by an efficient reinnervation by collateral sprouting of non-monoaminergic axons, which normally do not innervate the SCO cells. Morphologically, the reinnervating fibres totally replace the serotoninergic synapses lost by the lesion, but, functionally, they fail to substitute for the potent inhibitory control of secretory activity normally exerted by the serotoninergic innervation. It is possible that the observed reinnervation by foreign synapses explains why the regrowing serotoninergic neurons fail to re-establish their connections with the SCO.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01214803
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Development of serotonin-containing cells and the sympathetic innervation of the habenular region in the rat brain (1974)
    Springer
    Cell & tissue research 155 (1974), S. 231-243 
    Details
    ISSN: 1432-0878
    Keywords: Pinealocyte-resembling cells ; Habenular region ; Sympathetic nerve fibres ; Ontogenetic development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cells of the pineal gland, the pineal stalk, and the lamina intercalaris contain 5-HT and are innervated by sympathetic nerve fibres. These peripheral nerve fibres continue rostrally from the lamina intercalaris and run into the central nervous tissue of stria medullaris and the habenular nuclei. Pharmacological treatment to increase the cellular 5-HT content revealed that the sympathetic fibres are in close relation to yellow fluorescent cells embedded in the brain tissue. These yellow fluorescent cells develop very late in the ontogenetic development (three weeks or more postnatally) and are preceded by ingrowth of sympathetic fibres into the brain tissue. The results support the hypothesis that the cells found in the habenular region are of pinealocyte rather than neuronal nature, but it is possible that they differ in certain aspects from the cells of the pineal gland proper.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221357
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...